How to Use Headphone Power Calculator
The Headphone Power Calculator estimates the power, voltage and current required to drive a pair of headphones at a chosen volume. Enter the impedance and sensitivity, set a target SPL, and the Headphone Power Calculator instantly outputs required mW, Vrms and mA.
- Enter impedance — in ohms (Ω).
- Enter sensitivity — dB/mW or dB/V.
- Set target SPL — typically 100 dB for headroom.
- Read the result — required power, voltage and current.
Formula & Theory — Headphone Power Calculator
The Headphone Power Calculator uses Ohm’s law and the dB/mW sensitivity definition:
P = V² / R = I² × R
V = √(P × R)
I = V / R
For sensitivity in dB/mW: P (mW) = 10 ^ ((SPL - sensitivity) / 10)
For sensitivity in dB/V : V (Vrms) = 10 ^ ((SPL - sensitivity) / 20)| Symbol | Meaning |
|---|---|
| R | Headphone impedance (Ω) |
| V | Driving voltage (Vrms) |
| I | Current (A) |
| P | Power (W) |
Assumptions and Limits
The Headphone Power Calculator is informational. Real loudness depends on source quality, amplifier output, recording loudness and listener preference.
Use Cases for Headphone Power Calculator
- Picking an amplifier — see if a phone, dongle DAC or desktop amp is enough.
- Comparing headphones — sensitivity differences matter more than impedance.
- DIY audio — design a portable amp around real power requirements.
- Audio reviews — verify drivability claims with numbers.